[REVIEW] Port unary to libcudf++

CHANGELOG.md

@@ -136,7 +136,7 @@
 - PR #3380 Concatenate columns of strings
 - PR #3382 Add fill function for strings column
 - PR #3391 Move device_atomics_tests.cu files to legacy
-- PR #3303 Define and implement new stream compaction APIs `copy_if`, `drop_nulls`, 
+- PR #3303 Define and implement new stream compaction APIs `copy_if`, `drop_nulls`,
            `apply_boolean_mask`, `drop_duplicate` and `unique_count`.
 - PR #3387 Strings column gather function
 - PR #3440 Strings column scatter function
@@ -146,6 +146,7 @@
 - PR #3425 Strings column copy_if_else implementation
 - PR #3422 Move utilities to legacy
 - PR #3201 Define and implement new datetime_ops APIs
+- PR #3214 Port unary to libcudf++
 
 ## Bug Fixes
 

cpp/CMakeLists.txt

@@ -430,6 +430,8 @@ add_library(cudf
             src/unary/legacy/math_ops.cu
             src/unary/legacy/cast_ops.cu
             src/unary/legacy/null_ops.cu
+            src/unary/math_ops.cu
+            src/unary/unary_ops.cuh
             src/io/legacy/cuio_common.cpp
             src/io/legacy/io_functions.cpp
             src/io/convert/csr/legacy/cudf_to_csr.cu

cpp/include/cudf/unary.hpp

@@ -22,6 +22,37 @@
 namespace cudf {
 namespace experimental {
 
+enum class unary_op {
+  SIN,          // < Trigonometric sine
+  COS,          // < Trigonometric cosine
+  TAN,          // < Trigonometric tangent
+  ARCSIN,       // < Trigonometric sine inverse
+  ARCCOS,       // < Trigonometric cosine inverse
+  ARCTAN,       // < Trigonometric tangent inverse
+  EXP,          // < Exponential (base e, Euler number)
+  LOG,          // < Natural Logarithm (base e)
+  SQRT,         // < Square-root (x^0.5)
+  CEIL,         // < Smallest integer value not less than arg
+  FLOOR,        // < largest integer value not greater than arg
+  ABS,          // < Absolute value
+  BIT_INVERT,   // < Bitwise Not (~)
+  NOT,          // < Logical Not (!)
+};
+
+/**
+ * @brief Performs unary op on all values in column
+ *
+ * @param[in] input A `column_view` as input
+ * @param[in] op operation to perform
+ *
+ * @returns std::unique_ptr<cudf::column> Result of the operation
+ */
+std::unique_ptr<cudf::column> unary_operation(cudf::column_view const& input,
+                                              cudf::experimental::unary_op op,
+                                              cudaStream_t stream = 0,
+                                              rmm::mr::device_memory_resource* mr =
+                                              rmm::mr::get_default_resource());
+
 /**
  * @brief Creates a column of `BOOL8` elements where for every element in `input` `true`
  * indicates the value is null and `false` indicates the value is valid.

cpp/include/cudf/utilities/legacy/wrapper_types.hpp

@@ -350,17 +350,12 @@ using unwrapped_type_t = typename unwrapped_type<T>::type;
 
 } // namespace detail
 
-using category = detail::wrapper<int32_t, GDF_CATEGORY>;
-
+using category          = detail::wrapper<int32_t, GDF_CATEGORY>;
 using nvstring_category = detail::wrapper<int32_t, GDF_STRING_CATEGORY>;
-
-using timestamp = detail::wrapper<int64_t, GDF_TIMESTAMP>;
-
-using date32 = detail::wrapper<int32_t, GDF_DATE32>;
-
-using date64 = detail::wrapper<int64_t, GDF_DATE64>;
-
-using bool8 = detail::wrapper<int8_t, GDF_BOOL8>;
+using timestamp         = detail::wrapper<int64_t, GDF_TIMESTAMP>;
+using date32            = detail::wrapper<int32_t, GDF_DATE32>;
+using date64            = detail::wrapper<int64_t, GDF_DATE64>;
+using bool8             = detail::wrapper<int8_t, GDF_BOOL8>;
 
 // This is necessary for global, constant, non-fundamental types
 // We can't rely on --expt-relaxed-constexpr here because `bool8` is not a